Gas blast breaker with separately actuated blast valve and tank filling valve



P 1950 e. E. JANSSQN 2,521,460

GAS BLAST 1mm wrra SEPARATELY ACTUATED BLAST VALVE AND TANK FILLING VALVE Filed July 11, 1947 2 Sheets-Sheet 1 INVENTOR /Z 1 f3 wax/ow lowwa, 0W

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P 1950 GE. JANSSON 2,521,460

GAS BLAST BREAKER WITH SEPARATELY ACTUATED BLAST VALVE AND TANK FILLING VALVE Filed July 11, 1947 2 Sheets-Sheet 2 VENTOR E1 wJXa/v 8. 3 WOW ATKORNEY Pmma Sept. 5, 1950 BLAST BREAKER. WITH SEPARATELY ACTUATED BLAST VALVE AND TANK FILL- IN G VALVE Gustav E. Jansson, North Quincy, Masa, assignor to Allis-Cha lmers Manufacturing Company,

Milwaukee, Wis., a corporation oi Delaware Application July 11, 1941, Serial No. 760.258

Claims. (c1.2oo a1.4)

The present invention relates to electric circuit breakers of the gas blast type, and more particularlyto means for preventing re-establishment of the arc subsequent to a current zero with a minimum of consumption of arc extinguishing fluid.

The operation of gas blast circuit breakers requires a high initial blast intensity for establishing a high dielectric level across the gap formed between the separated contacts. Upon having establishedv the required dielectric level,

the same may be maintained by means of a blast of smaller intensity.

There exists for any given set of conditions a most desirable blast intensity-time characteristic.- In order to operate a circuit breaker with a minimum consumption of arc extinguishing fluid, the actual blast intensity-time characteristic must be as close as possible to the blastintensity-time characteristic which would be ideal under prevailing conditions.

Various arrangements may be used for obtaining any desired blast intensity-timecharacteristic. For instance, are extinguishing gas under pressure, e. g. compressed air,- may be supplied from a blast reservoir or breaker tank having a relatively limited capacity not substantially exceeding that required for one single interrupting process or may be, two interrupting processes. Upon initiation of the escape of are extinguishing fluid from a one-shot-tank, the pressure therein decreases rapidly, resulting in a rapid decrease of the blast intensity. Thus the blast intensity decreases rapidly to the relatively small magnitude required after circuit interruption for maintaining for a short time the proper dielectric level across the gap formed between the separated breaker contacts until additional circuit insulation can be introduced into the circuit. Because of this rapid decrease of blast intensity, a gas blast circuit breaker having a one-shot or similar small tank permits to be operated with a minimum consumption of arc extinguishing fluid.

Yet one-shot tank type circuit breakers are unsatisfactory in certain respects. Since it takes time to refill a blast reservoir or breaker tank by meanspf a compressor, one-shot-tank type circuit breakers are inapplicablewherever it is required to eilect more than one interrupting operation within a relatively short interval of time as, for instance, in the case of high-speed reclosing service.

For this reason it has become accepted practice, in cases involving a duty cycle comprising more than one interrupting operation occurring within a short interval oftime, to provide gas blast circuit breakers with a blast reservoir or breaker tank having relatively large dimensions and suflicient storage capacity to supply the amount of arc extinguishing fluid required for a. plurality of interrupting operations. In circuit breakers having such oversized breaker tanks there is, subsequent to initiation of the escape of an arc extinguishing gas blast therefrom, a slow decrease of the tank pressure. This results in maintaining a gas blast of larger magnitude than required for preventing re-establishment of the are after initial arc extinction. Consequently, such arrangements are uneconomical.

Another type of gas blast circuit breakers comprises a blast reservoir or breaker tank from which the are extinguishing blast is derived, and,

. in addition thereto, another fluid reservoir or storage tank which is connected to the blast reservoir or breaker tank by a fluid conduit of relatively large cross-section. That fluid conduit is controlled by a diflerential valve which is normally biased to the open position thereof, but closes when, owing to opening of the blast valve of the circuit breaker, the diflerence in pressure between the two aforementioned reservoirs or tanks increases beyond a predetermined value. Since the drop of pressure occurring upon opening of the blast valve is very rapid, this results in rapid closing of the diiferential valve, thus making it possible to obtain a favorable blast intensity-time characteristic similar to that which can be obtained when using a one-shot or similar small-capacity tank. This type of circuit breaker comprises, in addition to the differential valvecontrolled tank-interconnecting conduit which has a relatively large cross-section, a tank interconnecting conduit of relatively smaller crosssection, which is permanently open. Upon closing of the blast valve the pressure in the blast reservoir or breaker tank increases gradually owing to the leakage flow of gas under pressure through the permanently open tank interconnecting conduit of relatively small cross-section. When, owing to that leakage flow, the pressure in the breaker tank reaches a predetermined value, the large tank-interconnecting conduit is opened by the operationof the differential valve which is arranged therein, thus resulting in equalization of the pressure within the two tanks. It is apparent that it requires a relatively long time for the leakage flow between the two tanks to cause the diilerential valve to open and to make the circuit breaker therebyready for a second circuit interrupting operation. For this reason circuit breakers which are provided with a differential valve-interconnected two-tank pressure fluid system do not lend themselves very readily to applications involving rapidly recurring circuit interruptions as required, for instance, in the case of high-speed reclosing service. Nor do such circuit breakers lend themselves to a perfect coordination of the operation of the blast valve and the tank interconnecting valve.

It is, therefore, one object of the present invention to provide a circuit breaker of the fluid or gas blast type which permits rapid sequential interrupting operations with a minimum of consum-ption of arc extinguishing fluid or gas and which lends itself to high-speed reclosing service. Another object of the present invention is to provide a circuit breaker of the type comprising a breaker tank, a storage tank, and a valve interconnecting said two tanks wherein said valve is positively actuated independently of the difler-- ence in fluid pressure between said tanks.

Another object of the present invention is to provide a circuit breaker comprising a pressure fluid system of the two-tank type wherein the valve for replenishing the breaker tank from the storage tank is opened instantly by positive action upon complete interruption of the circuit rather than being opened by spring or similar means after a predetermined time delayfollowing reclosing of the blast valve.

Another object of the present invention is to provide a circuit breaker of the aforementioned type wherein the valve for replenishing the breaker tank from the storage tank is closed at the point of time of opening of the valve which controls the arc extinguishing blast rather than being closed only subsequent to the opening of said blast valve.

A still further object of the present invention is to provide a circuit breaker of the aforementioned type wherein a motor which must be present in the circuit breaker on account of reasons not related to the tank-interconnecting valve is used, in addition to its primary function, for operating said valve.

Objects and advantages other than those above described will be apparent from the following description when read in connection with the accompanying drawing, in which:

Fig. 1 is a view, partly in vertical cross-section and partly in side elevation, of a circuit breaker of the axial blast type, designed for outdoor service, and embodying the features of the present invention;

Fig. 2 is a diagrammatic representation of a circuit breaker of the cross-blast type, designed for indoor service, and embodying the features of the present invention; and

Fig. 3 shows a cross-section through certain details of a modification of the mechanism for operating the tank-interconnecting valve.

Referring more particularly to the drawing by characters of reference, Fig. 1 illustrates a high voltage circuit breaker comprising a movable contact i which cooperates with a tubular stationary contact 2 to make or break an electric circuit. Movable contact I is operated by a toggle linkage 3 which is actuated by a reciprocating rod 4'. Flexible conductor 5 connects contact I to the terminal element 8. Movable contact I is arranged within a tubular insulator 6 forming an arcing chamber. The stationary contact 2 supports a tubular insulator 1 covered by a hood 1a which serve as an exhaust as well as a cooling means for are products. The upper part and the lower part of the circuit breaker column are provided each with a terminal element The lower terminal element a is connected by means of conductor to to the terminal element id of a disconnect switch which has been generally indicated by the reference number I. Disconnect switch 9 is adapted to be operated by a fluid motor ll comprising a cylinder Ilc, a piston lid and venting means not shown in the drawing. The tubular insulators or form a housing for accommodating the contact members lb, 90 of disconnect switch 9. Stationary tulip shape contact 9b, arranged on the top of the upper insulator la, is adapted to cooperate with the movable rod shape contact 00. The latter may be actuated by fluid motor I. through the intermediary of rock shaft lb and crank mechanism Ida. If both the circuit breaker proper and the disconnect switch 3 are closed, the following circuit is established: Upper terminal element I, contact members 2, 1, lower terminal element I, conductor 8a, terminal element 8d, contact rod lo,

and tulip shape contact lb. Contacts I, 2 and contacts 9b, 9c, are supposed to be opened sequentially, the former for effecting initial circuit interruption and the latter for .interposlng additional circuit insulation into the circuit upon interruption thereof by separation of contacts I, 2 and the action'of an arc extinguishing blast.

A tubular insulatorli supports the circuit breaker column consisting of the tubular insulator 6 and the aforementioned parts which are associated therewith.

A source of fluid under pressure, such as the compressor 12, may supply fluid under pressure through a pipeline 13, including check valve ll, to the storage reservoir or storage tank ll. Storage tank I! is connected by means of tubular structure ii to breaker tank l1. Breaker tank I1 has sufllcient storage capacity for effecting one or two circuit interruptions. Pipe it, which includes a check valve It, is adapted to supply breaker tank i1with fluid under pressure directiy from compressor 12. It will be noted that the cross-section of pipes i3 and I2 is relatively small, while the cross-section of tubular structure I6 is relatively large. Blast tube 2| connects breaker tank 11 and tubular supporting insulator II. The flow of fluid under pressure from tank IE to tank i1 is controlled by valve 2|. Valve 2| is biased to the closed position thereof by spring 22. It can be opened, against the action of said spring, by means of fluid motor 10, rocking shaft llib, and a crank mechanism including push rod 23. Push rod 23 is connected to actuator 24 adapted to pivot aboutfulcrum 25.

In Fig. 1 rocking shaft 10b is shown in a position causing separation of contacts 9b, 9c and opening of valve 21 against the action of biasing spring 22. If rocking shaft llb is rotated by motor ill in a clockwise direction, this causes contact to engage contact 9b and frees stem 26 of valve 21, thus permitting biasing spring 22 to reclose that valve.

Blast tube 20 is under the control ofa blast valve which has generally been indicated by reference sign 21. Blast valve 21 is adapted to be operated by a fluid motor of the differential type which includes a cylinder 28a, 9. piston 28b, and a biasing spring 28c. Piston 28b serves as movable valve body and is adapted to engage valve seat 28d, and spring 28c tends to keep valve 21 in the closed position thereof. Operation of fluid motor 21 may be initiated by operation of solenoid trip valve 29, Normally fluid under pressure is being suppliedto both sides of piston 28b. the left side of cylinder 2811. being supplied with fluid under pressure from tank |1 through pipe .39. Upon energizing of solenoid trip valve 29, the left end of cylinder 29a is vented to atmosphere, thereby causing blast valve 21 to open.

Passage 3| is adapted to supply a fluid motor which has been generally designated by reference numeral 32 with fluid under pressure derived from the inside of insulator 6. Fluid motor 32 which includes a relatively'movable cylinder 39 and piston 36 is adapted to operate operating rod 4 for separating contacts and 2. Air under pressure flowing through passages 3| causes piston 36 of fluid motor 32 to move from right to left, resulting in moving operating rod 4 from right to left, and consequently in separation of contacts I and 2. Spring 31 biases motor 32 to contact closed position and effects closing of contacts I and 2 upon closing of blast valve 21. Cylinder 39 is adapted to be vented during the closing stroke of the breaker by means of air ducts 34 which are controlled by a check-valve 35.

Normally blast valve 21 is closed by reason of the action of its biasing spring 290. When trip valve 29 is energized, the left side of cylinder 28a is vented, while air under pressure acting upon the right end surface of piston 29b causes valve 21 to open. When piston or valve body 28b of blast valve 21 is lifted from its seat 28d, a blast of fluid under pressure rushes through blast tube and tubular supporting insulator into the arcing chamber formed by tubular insulator 6. The portion of the blast which branches off through conduit 3| causes the contacts 2 to separate, as described above. An are is initiated between the separating contacts 2 and is acted upon by a blast of arc extinguishing gas under pressure which escapes through contact 2, insulator 1 and hood 1a. The blast storage capacity of tank i1 is suflicient for at least one complete interrupting opera:

tion, i. e., that tank is capable of supplying one initial high-intensity blast and one subsequent low intensity blast which lasts until the contacts 9b, 9c of the disconnect switch 9 have parted a safe distance. Consumption of fluid under pressure beyond the quantity needed for are extinction and for maintaining temporarily the required dielectric level between the separated contacts 2, is strictly precluded by reason of the fact that tube It remains closed as long as valve 2| is not opened by the operation of motor l0. Valve 2| is being opened while fluid motor l0 completes its stroke separating contacts 9b, 90, thus rapidly increasing the pressure level in tank H to the amount required for a subsequent interrupting operation.

Conduit l8 helps increase the speed of restoring pressure in tank l1 by fluid under pressure directly derived from compressor l2, but may be omitted if this particular feature is not deemed necessary.

Fluid motor I0 is supplied with fluid under pressure through pipe 40 branching oil blast tube 20 at a point situated downstream with respect to blast valve 21. Sequential contact separating operations of fluid motors 32 and I0 can be insured by proper selection of the crosssectlons of fluid conduits 3| and 40 and proper adjustment of needle valve 40a.

Upon interruption of the circuit, contacts 2 are being reclosed by the action of spring 31. This. however, does not result in reclosing oi the circuit. since contacts 9b, 9c are separated'before contacts -2 are reclosed. Reclosing of the circult is effected by causing contacts 3b, 3c to re-engage while contacts 1, 2 are in engaged position. Upon energization of closing solenoid valve 4|, fluid under pressure is allowed to rush through pipe 42 to fluid motor i9, resulting in closing of contacts 3b, 3c and freeing of stem 29 of valve 2|, thus permitting biasing spring 22 to close that valve.

In Fig. 2 the same reference numerals as in Fig. 1 have been supplied tolike parts. Thus, I 5 indicates a storage tank, H a breaker tank, l6 passage means interconnecting tanks l5 and I1, and 2| a valve for controlling the flow of fluid through passage means l8. Stem 28 of valve 2| is biased to the closed position thereof by means of biasing spring 22. Tank l5 can be supplied with fluid under pressure (from a source not shown) through pipe l3 and check valve I4. Tank I! can directly be supplied with fluid under pressure through by-pass pipe l8 and check valve l9. Blast valve 21 controls the flow of fluid through blast tube 20. The electrical circuit of the breaker comprises upper terminal member 3, stationary flnger'contacts 2 adapted to engage movable contact I, movable blade contact and lower terminal members. Contact is hinged at 43 and can be operated by means of fluid motor 32 comprising cylinder 39 and piston 36 operatively arranged therein. Pipe 3| is adapted to supply'one of both ends of cylinder 39 with fluid under pressure. A linkage including piston rod 45 interconnects piston 36 and lever 45. Lever 45 is journalled in bearing 41. Operating rod 65 is hinged to contact and lever 45, respectively. A projection 35a on lever 45 is adapted to engage stem 26 of valve 2| for moving said valve into the open position thereof. The circuit breaker comprises further an arc chute 50 including a plurality of arc splitters or partitions 5|, which subdivide the chute into a plurality of blast passages 38. Partitions 5| converge toward the blast entrance and diverge toward the exhaust portion of chute 50. Blast valve 21 is adapted to be operated by fluid motor 28 which may be supplied with fluid under pressure from tank i1 through pipe 30 and solenoid trip valve 29. Opening of the latter causes fluid motor 28 to be supplied with fluid under pressure, resulting in opening of blast valve 21. This, in turn, causes a blast of fluid under pressure to rush through blast tube 23 and are chute 50. Branch conduit 3| supplies fluid motor 32 with fluid under pressure. Fluid motor 32, upon being supplied with fluid under pressure, rotates lever 45 about fulcrum 41 in a clockwise direction. This causes separation of contacts and 2 and the arc formed'therebetween is extinguished by the blast of gas under pressure flowing through blast tube 20. The are will be extinguished and the circuit interrupted before contact blade I leaves are chute structure 50. During the initial separation of contacts I, 2 extension 45a of lever 45 does not engage stem 26 of valve 2| and, therefore, valve 2| remains closed. It is necessary, upon extinction of the arc, i. e., interruption of the circuit, to interpose additional insulation into the circuit by increasing the amount of separation of contacts and 2. To this end, fluid motor 32 is caused to move lever 45 and contact blade I under pressure from tank II to tank ll.

Opening of solenoid closing valve 2| causes fluid motor 22 to be supplied through pipe II with fluid under pressure from tank l1 and to close the breaker, simultaneously permitting biasing spring 22 to reclose valve 2|, thus precluding any further flow oi fluid from storage tank lltobreakertank l1.

Reierring now to Fig. 8, this iigure shows a storage tank |5, a breaker tank i1 and a tank interconnecting valve 2| arranged in a passage ll. Valve 2| comprises the stem 2 and the closing biasing spring 22. The flow oi fluid through blast tube 2| and branch tube ll is controlled by means of blast valve 21. Tube 4| branches out into branches a and b adapted to supply simultaneously both ends oi a cylinder 7 II with fluid under pressure. Piston I which is operatively arranged in cylinder It remains in its upper position as long as blast valve 21 remains closed, it being held in that position by the action of valve biasing spring 22 Passage a is provided with a check valve II and the head of cylinder I2 is provided with needle valve II. It fluid under pressure is supplied simultaneously through branch passages a and b in iront andback of piston II, this will initially have no eifect whatever on piston ll. Upon reclosing of blast valve 21 there will be a backflow of fluid under pressure from cylinder it through branch pipe 40b into blast tube 2!. ing to the presence oi check valve II a similar backflow cannot occur irom cylinder it through branch pipe "a. Consequently, the pressure on one side of piston It will soon exceed the pressure on the other" side thereof, resulting in a downward movement of piston l4, whereby valve 2| will be opened. The point of time at which piston 34 will open valve 2| can be properly adiusted by means oi needle valve It, the adjustment of which aflects the rate of bleeding of the 'top of cylinder 83.

Since the backflow oi fluid under pressure from reciosing of blast valve 21, it follows that reclosing of valve 21 and opening of valve 2| are eflected sequentially. This sequence is important in order to preclude replenishing of tank I'I from tank I! prior to reclosing 01' valve 21 which, it permitted to occur, would result in 5 waste oi fluid under pressure.

A similar sequential operation of valves 21 and 2| can be achieved by the means shown in' Fig. 1. To this end, an auxiliary switch 52 is included into the circuit of trip solenoid valve 22, which switch is under the control of motor II in such a way as to cause opening of the circuit of trip solenoid valve 2! sumciently'prior to the opening of valve 2| by rocking shaft llb.

Although but some embodiments of the present invention have been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit oi the invention or from the scope of the appended claims.

. cylinder 53 to blast tube 20 will be initiated upon 8 Pltiiiuizclaimedandciesiredtoaecnrabylietters LIdacircuitbreakerthecombinationois pair or oper ting contacts, contact separating means,asourceoifluidunderpresure,aflrat reservoir adapted-to be supplied with fluid under pressureiromsaidsouree,asecondreservoir,a flrst valve interconnecting said flrst reservoir and said second reservoir, means for causing said valve to be normally maintained in the closed position thereof, a second valve connected to said second reservoir and adapted to control a flow of an arc extinguishing blast from said second reservoir adjacent said pair of contacts, and means operative independently of the difference in fluid pressure between said reservoirs for opening said first valve upon separation oi said contacts.

2. In a circuit breaker the combination or an arcing chamber, a pair of cooperating contacts arranged in said chamber, contact separating means, a source of fluid under pressure, a flrst reservoir adapted to be supplied with fluid under pressure from said source, a second reservoir, a flrst passage means connecting said flrst reservoir and said second reservoir, a flrst valve ior controlling a flow oi fluid through said flrst passage means, means for causing said valve to be normally maintained in the closed positon thereof, a flrst fluid motor operative independently of the difl'erence in fluid pressure between said reservoirs for opening said flrst valve, a second passage means connecting said second reservoir and said arcing chamber, a second valve for controlling a flow of fluid through said second passage means, a second fluid motor for operating said second valve, and means for initiating the valve opening stroke or said flrst fluid motor by the valve opening stroke oi said second fluid motor.

3. In a circuit breaker the combination oi a pair oi. cooperating contacts, contact separating means, a source oi fluid under pressure, a flrst reservoir adapted to be supplied with fluid under pressure from said source, a second reservoir, a-flrst valve interconnecting said flrst reservoir and said second reservoir, means for causing said flrst valve to be normally maintained in the closed position thereof, a second valv connected to said second reservoir and adapted to control a flow of arc extinguishing blast from said second reservoir adjacent said pair oi contacts, means for sequentially opening said pair of contacts and said flrst valve, said means including a fluid motor for opening said flrst valve operative independently of the diflerence oi. fluid pressure between said reservoirs, and means for supplying said fluid motor with fluid under pressure directly derived from said second reservoir. 4. In a circuit breaker the combination of a pair of cooperating contacts, contact separating means, a source of fluid under pressure, a flrst reservoir adapted to be supplied with fluid from said source, a second reservoir, a flrst valve interconnecting said flrst reservoir and said second reservoir, a blast tube for the passage or a blast of fluid under pressure from said second reservoir adjacent said pair 0! contacts, a second valve arranged in said blast tube for controlling said blast oi fluid under pressure, a fluid motor for operating said flrst valve, and a passage means for supplyin said motor with fluid under pressure, said passage means branching oi! said blast tube at a point situated downstream with respect to said second valve.

5. In combination, a circuit breaker comprising a pair oi cooperating arcing contacts connected in series with a pair of cooperating disconnect contacts; contact separating means for said arcing contacts, a source of fluid under pressure, a first reservoir adapted to be supplied with fluid under pressure from said source, a second reservoir, afirst valveinterconnecting said first reservoir and said second reservoir, means for causing said valve to be normally maintained in the closed position thereof, a second valve connected to said second reservoir and adapted to control a flow of arc extinguishing blast adjacent said pair of arcing contacts, means for separating said disconnect contacts upon separation of said arcing contacts, and mechanical means actuated by said disconnect contact separating means upon a predetermined movement of said disconnect contacts for opening said first valve.

6. In combination, a, circuit breaker compris i ing a pair of cooperating arcing contacts 'con-" nected in series with a pair of cooperating disconnect contacts, contact separating means for said arcing contacts, a source of fluid under pressure, a first tank adapted to be supplied with fluid under pressure from said source, a second tank, a first valve interconnecting said first tank and said second tank, a closing biasing means associated with said valve, a second valve connected to said second tank and adapted to control a flow of arc extinguishing blast adjacent said pair of arcing contacts, means for separating said disconnect contacts upon separation of said arcing contacts, a rock shaft for operating said disconnect contact separating means, a, fluid motor for operating said rock shaft, and means under the control of said rock shaft for opening said first valve against the action of said closing biasing means.

'7. In combination, a circuit breaker comprising cooperating arcing contacts and cooperating disconnect contacts serially connected with said arcing contacts, a source of fluid under pressure, a storage tank adapted to be supplied with fluid under pressure from said source, a breaker tank,

a first valve interconnecting said storage tank and said breaker tank, means for normally maintaining said valve in the closed position thereof, a second valve connected to said breaker tank and adapted to control a flow of arc extinguishing blast from said breaker tank adjacent said arcing contacts, and means for sequentially opening said arcing contacts and said disconnect contacts, said means including a common fluid motor for opening said disconnect contacts and said first valve.

8. In combination, a circuit breaker compristank adapted to be supplied with fluid under pressure from said source, a breaker tank, a first valve interconnecting said storage tank and said breaker tank, a second valve connected to said breaker tank and adapted to control a flow of arc extinguishing blast from said breaker tank adjacent said contacts, means for causing said first valve to be normally maintained in the closed position thereof, a motor operative independently of the difference in fluid pressure between said tanks for operating said first valve, and control means for causing sequential 'opening of said second valve and said-.first valve.

10. In combination, a"circuit-breaker comprising cooperating a-rcing contacts and cooperating disconnect contacts serially connected with said arcing contacts, means for opening said arcing contacts, a source of fluid under pressure, a storage tank adapted to be supplied with fluid under a motor, a common actuating structure operated by said motor for opening said disconnect con tacts and said first valve, said structure being also adapted to reclose said disconnect contacts upon separation thereof and to cause closing of said first valve concurrently with any such reclosing.

- 11. In a circuit breaker the combination of a pair of cooperating contacts, a source of fluid under pressure, a storage tank adapted to be supplied with fluid under pressure from said source, a breaker tank, a first valve interconnecting said storage tank and said breaker tank, means for biasing said valve to the closed position thereof, a second valve connected to said breaker tank and adapted to control a flow'of are extinguishing blast from said breaker tank adjaing cooperating arcing contacts and cooperating I disconnect contacts serially connected with said arcing contacts, a source of fluid under pressure,

a storage tank adapted to be supplied with fluid under pressure from said source, a breaker tank, a first valve interconnecting said storage tank and said breaker tank, means for biasing said valve to the closed position thereof, a second valve connected to said breaker tank and adapted to control a flow of arc extinguishing blast from said breaker tank adjacent said arcing contacts, and means for sequentially opening said arcing contacts and said disconnect contacts including a rock shaft adapted to separate said disconnect contacts,. and a rocking lever under the control of said rock shaft for actuating said first valve to the open position thereof.

9. In a circuit breaker the combination of a pair of cooperating contactacontact separating means, a source of fluid under pressure, a storage cent said pair of contacts, and common actuating valve, said common means being also adapted to reclose said contacts upon separation thereof and to permit said biasing means to close said first valve concurrently with any such reclosing.

12. In a circuit breaker the combination of an arcing chamber, a pair of cooperating contacts arranged in said chamber, a fluid motor for opening said contacts, a source of fluid under pressure, a storage tank adapted to be supplied with fluid under pressure from said source, a breaker tank, a first passage means connecting said storage tank and said breaker tank, a first valve for controlling a flow of fluid through said first passage means, means for causing said valve to be normally maintained in the closed position thereof, a second passage means connecting said breaker tank and said arcing chamber, a second valve for controlling a flow of fluid through said second passage means, and mechanical means for causing said first valve to be opened by said contact opening fluid motor concurrently with any contact opening operation thereof.

13. In a circuit breaker, the combination of a) pair of cooperating contacts, contact separating means, a source of fiuid under pressure, a first reservoir adapted to be supplied with fluid under pressure from said source, a second reservoir, a

first valve interconnecting said first reservoir and said second reservoir, means for causing said valve to b normally maintained in the closed 11 position thereof, a second valve connected to said second reservoir and adapted to control a flow of arc extinguishing blast from said second reservoir adjacent said pair of contacts, a fluid motor for opening said flrst valve comprising a cylinder and a piston operatively arranged therein, passage means under the control of said second valve for supplying fluid under pressure to said cylinder simultaneously to both ends thereof, and means for causing bleeding of fluid under pressure from said cylinder at a different rate at both ends thereof.

14. In a circuit breaker the combination of a pair of cooperating contacts, contact separating means, a source of fluid under pressure, a first reservoir adapted to be supplied with fluid under pressure from said source, a second reservoir, a first valve interconnecting said flrst reservoir and said second reservoir, means for causing said valve to be normally maintained in the closed position thereof, a second valve connected to said second reservoir and adapted to admit a flow of arc extinguishing blast from said second reservoir adjacent said pair of contacts, means for reclosing said second valve upon separation of said contacts, and means operative independently of the difference in fluid pressure between said reservoirs for causing opening of said flrst valve upon recloslng of said second valve.

15. In a circuit breaker, the combination of a pair of cooperating arcing contacts in series with a pair of cooperating disconnect contacts, contact separating means for said arcing contacts, a source of fluid under pressure, a flrst reservoir, passage means having a relatively small cross- 39 Number 12 sectionforconnecflngsaidsourcewithsaidflrst reservoir, a second reservoir, passage means having a relatively large cram-section for interconnecting said flrst reservoir and said second reservoir. a flrst valve for controlling the flow of fluid from said flrst reservoir into said second reservoir, means for causing said valve to be normally maintained in the closed position thereof, a second valve for controlling an arc extinguishing blast of fluid irom said second reservoir adjacent said pair of arcing contacts, means responsive to the opening of said second valve for separating said disconnect contacts and for causing opening of said flrst valve, said disconnect contact separating means including a reciprocating fluid motor having an open disconnect con- .tact position and a closed disconnect contact position, and means under the control of said fluid motor for causing said flrst valve to close concurrently with an operation of said fluid motor from the open disconnect contact position to the closed disconnect contact position thereof.

GUSTAV 1!. JANSSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

